A maverick detective is one of the oldest stock characters in popular entertainment: the drinker, the brawler, the loner who bends the rules. It is a hoary television tradition that dictates that, just as surely as the hero will eventually be given 24 hours to bring in the evidence, his domestic dynamic will revolve around whether or not his patient girlfriend, or possibly ex-wife, will put up with all the grief.

Now, however, a new stable of highly strung female detectives has taken charge of the crime scene, equipped with the sort of extreme psychological problems that rival those of the killers and terrorists they are tracking down.

Chief among these fresh recruits is Carrie Mathison, the bipolar obsessive played by Claire Danes in the hit US series Homeland, now showing on Channel 4. Not only is Mathison an unreliable central character, she has to covertly get hold of drugs to stabilise her condition. If she reveals her mental health history, she will lose her job with the CIA and, the viewer fears, the convert to Islam who has become a fundamentalist that she is secretly watching will go unpunished.

"She is a mess," Danes has said. "I don't really spend much time thinking about seducing an audience or protecting her status as being appealing or likeable. I find the challenge is finding a way to play the truth of her being chemically unstable and also a really proficient, highly capable CIA agent. How can those two things coexist?"

Mathison's condition means she has no discernible interest in friends, a social life or family. Instead, she intermittently paints her toenails, puts on a glittery top and goes to a bar to pick up a one-night stand. Danes's agent is perhaps the most glamorous and most convincingly unruly sleuth in a stressed-out line-up that now includes the alienated and abused geek Lisbeth Salander from Stieg Larsson's Swedish Millennium trilogy, the socially inept Sarah Lund from The Killing and, most recently, the damaged and isolated Katrine Ries Jensen, played by Laura Bach, in the Danish police procedural Those Who Kill, the show bought by ITV3 as a bid for its own chic, psychologically challenged leading lady.

Danes's portrayal of Mathison has won critical praise, earning her a Golden Globe for best actress, and the role pushes the concept of a flawed heroine into unexplored territory: her reliance on pharmaceuticals appears to keep her either on-track, or off it – the viewer is not quite sure.

The actress, now 32, is one of those rare talents to survive an early break into showbusiness as a child star. She appeared on a number of mainstream US television series as a girl and teenager and received her first Golden Globe, along with an Emmy nomination, for playing a 15-year-old in acclaimed drama series My So-Called Life, although the show was cancelled after 19 episodes.

"We were doing something that turned out to be really relevant and lasting, but how could I have any clue?" Danes has said. "I had no idea what the Golden Globes were. But I knew a lot about being miserable and 14 and that's all I needed to know. When we shot the pilot, it was before I had even been in high school. I stopped going to school and started to live in a soundstage version of it."

Moving to the big screen for the 1994 film adaptation of Little Women, Danes also appeared as Holly Hunter's daughter in Home for the Holidays, directed by her heroine, Jodie Foster. But the actress grabbed international attention in 1996 when she played Juliet to Leonardo DiCaprio's Romeo in Baz Luhrmann's Romeo + Juliet. After making films directed by Francis Ford Coppola and Oliver Stone, Danes then took a leaf from Foster's book and left her career temporarily to study at Yale.

"I knew that I was young and hadn't really explored all of my interests as fully as possible, so I wasn't entirely sure if I was acting out of habit or real desire, and sure enough the latter proved to be true, but I just feel safer now, being certain of that," she has explained, adding that her film star status quickly palled at Yale, where everyone else was "sort of extraordinary and a little odd".

Her two years there, she has said, gave her an understanding of what kind of acting she wanted to do, but it is not something a star can always put into practice.

"So much of it is not up to us, especially in film. Our roles are filtered through so many different people, the director, the editor. What ends up on the screen is not necessarily what we intended to do."

In 2002, Danes returned to Hollywood, co-starring, among other parts, as Meryl Streep's daughter in the Oscar-nominated The Hours. In 2007, she appeared in the fantasy Stardust, a film she described as a "classic model of romantic comedy". This was followed by a Broadway stage debut as Eliza Doolittle in Pygmalion, but she says that she is also drawn to painting and dancing, which provide a sense of direction and order that are missing for an actor on a film set.

"I probably would paint before I would direct," she said recently. "My parents were visual artists so I grew up drawing and I've been dancing again the last four years. I can return to that in time and I have much more control over that."

Danes, who is married to British actor Hugh Dancy, won another Golden Globe last year for playing an autistic woman in HBO's series Temple Grandin. She clearly took the job of representing the condition on screen seriously. "I worked with a dialogue coach and she really did assemble a Rosetta Stone of how Temple would speak. I still sometimes revert to Temple-speak."

To research the role of CIA agent Mathison for Homeland, she also visited real agents in their workplace and asked them about the part that gender and sex play in their work: "It can be an asset and used to their advantage, but it can also be problematic, and then they have to be creative about how to resolve that. It's a real issue in Arab cultures, where men don't have relationships with women like we do here."

More relevant perhaps than gender to the role though is the mental status of Mathison. Just like Salander, Lund and Ries Jensen, the social deficiencies of the character are linked to their particular skill. It seems that female detectives, unlike their male counterparts, must be more than just maverick.

"I joke that she [Mathison] responds really well to the meds, but I have to believe that is true," Danes has recently revealed. "We're still deciding where she's at on that spectrum. She probably has a more modest condition. They're related in some ways [the job and the disorder]. They both involve paranoia, and when somebody's mind is susceptible to that, they're constantly questioning themselves and the world around them and that translates pretty easily into her work."

When Helen Mirren's apparently competent Jane Tennison is shown reaching for the bottle in Prime Suspect, the scene will never have the same impact again.